What is the concept of C++ containers?

C++ containers are objects used for storing and managing a group of data elements. They offer a convenient way to organize and access data, while also providing a set of operations for adding, deleting, searching, and sorting data.

The C++ standard library offers various container types, including sequence containers (such as vector, list, deque), associative containers (such as set, map, multiset, multimap), and unordered containers (such as unordered_set, unordered_map, unordered_multiset, unordered_multimap).

容器的概念包括以下几个方面：

1. Data storage: containers can store various types of data elements, including primitive types, custom types, or other containers.
2. Data organization: Containers structure data in specific ways, such as sequence containers storing elements in linear order and associative containers storing elements based on key values.
3. Data access: Containers offer various ways to access and manipulate data, such as accessing by index, iterating through iterators, and looping through ranges.
4. Data manipulation: The container offers a range of operations for adding, removing, searching, sorting, merging data, etc., to meet various needs.
5. Memory management: Containers are responsible for managing the allocation and deallocation of memory for data, automatically expanding or shrinking memory space to improve program efficiency and flexibility.
6. Characteristics and performance: Different types of containers have varying features and performance characteristics. Selecting the appropriate container can enhance the efficiency and performance of the program.

In general, C++ containers offer a flexible and efficient way to store and manipulate data, making program development more convenient and efficient.